diff --git a/htdocs/includes/modules/facture/saturne/saturne.modules.php b/htdocs/includes/modules/facture/saturne/saturne.modules.php
index f99d27ca093..861525270d6 100644
--- a/htdocs/includes/modules/facture/saturne/saturne.modules.php
+++ b/htdocs/includes/modules/facture/saturne/saturne.modules.php
@@ -56,7 +56,7 @@ class mod_facture_saturne extends ModeleNumRefFactures
      *      \param      objsoc      Objet société
      *      \return     string      Texte descripif
      */
-    function getNumRef($objsoc=0, $prefixe_additionnel='')
+    function getNumRef($objsoc=0, $prefixe_additionnel)
     { 
        
       $y = strftime("%y",time());